| Academic Talent Program | Academic & Science |
| Atmospheric Pressure | Academic & Science |
| Aerobic Treatment Process | Academic & Science |
| Authorised Training Principal | Accounts and Finance |
| Aitape | Airport Code |
| Aluminum Tire Pump | Business |
| Ability To Pay | Business |
| Advanced Technology Products | Business |
| Advance Training Project | Business |
| Accredited Tax Preparer | Business |
| Atlantic Power Corporation | Business |
| Atlas Pacific LTD. | Business |
| Across The Pond | Business |
| Advanced Test Products | Business |
| American Tennis Psychologists | Business |
| Ambient Temperature Pressure | Chemistry |
| All Trace Particles | Chemistry |
| Adenosine Tri-phosphate | Chemistry |
| Attempt To Please | Community |
| Academically Talented Program | Community |
| Action Team for Partnership | Community |
| Armenia Tree Project | Community |
| Alcohol Treatment Program | Community |
| All Things Possible | Community |
| Approved Training Provider | Community |
| Association of Test Publishers | Community |
| Association for the Tutoring Profession | Community |
| Administrators Teachers and Parents | Community |
| Automated Test Panel | Computing |
| Advanced Technology Program | Computing |
| Authorised Training Partner | Computing |
| Advanced Technology Projects | Computing |
| Arcade Third Person | Computing |
| Adaptive Threshold Processor | Computing |
| Array Transform Processor | Computing |
| Available To Promise | Computing |
| Assembly, Testing, and Packaging | Computing |
| Agent Transfer Protocol | Computing |
| Administrators Tools Pack | Computing |
| Atlanta Technology Professionals | Computing |
| Alps Tunneling Protocol | Computing |
| Advanced Technology Provider | Computing |
| Advanced Threat Protection | Computing |
| All Tests Passed | Computing |
| All Tests Pass | Computing |
| Application Transaction Processing | Computing |
| Anti Track Premium | Computing |
| Advanced Tool Pack | Computing |
| Advanced Technology Programs | Computing |
| Assistive Technology Professional | Computing |
| Alaya | Cryptocurrency |
| Atlas Protocol | Cryptocurrency |
| Autotransformer Thermal Protection | Electronics |
| Ask The Populars | General |
| All Terrain Professional | General |
| Availability To Promise | General |
| Adenosine Triphosphate The P | General |
| Advance Trainfire Program | General |
| Another Teaching Period | General |
| Adenisyne Tri Phosphate | General |
| Adenosine Tri Phosphatea | General |
| Adaption To Technical Progress | General |
| Association of Topping Pandas | General |
| Automotive Technology Program | General |
| Alliance Truck Parts | General |
| All Terrain Pattern | General |
| Audi Technology Portal | General |
| Associated Truck Parts | General |
| Automatic Transmission Parking | General |
| Amg Track Package | General |
| Airport Taxicab Permit | General |
| Advanced Telematics Platform | General |
| Audi Talent Programme | General |
| Automotive Theft Protection | General |
| Auto Tow Protection | General |
| Amg Track Pace | General |
| Audi Transformation Plan | General |
| All The People | General |
| adenosine triphosphate In processes | General |
| Agricultural Trade Promotion | General |
| Aircraft Technical Publishers | General |
| Antimicrobial Testing Program | General |
| Administrative Transformation Program | General |
| Apple Tree Partners | General |
| Advanced Technology Package | General |
| Adjustable Throttle Pedal | General |
| All Terrain Pick-Up | General |
| Automotive Telemetry Protocol | General |
| Anti Theft Protection | General |
| Advanced Theft Protection | General |
| Automotive Technology Platform | General |
| Al The Pal | General |
| All Terrain Pikachu | General |
| All Tomorrows Party | General |
| All Tomorrows Parties | General |
| Alternate Test Procedures | General |
| Alternative Transients Program | General |
| Accidental Tech Podcast | General |
| Alert Transponder Panel | General |
| Airline Transport Pilot | General |
| Adenosine Triphosphate PubChem | General |
| Automatic Transmission Parts | General |
| All That Power | Governmental |
| Army Techniques Publications | Governmental |
| Accorde Transports Perissable | Governmental |
| Alternative Transient Program | Governmental |
| Active Transportation Program | Governmental |
| Airline Transport Pilots | Governmental |
| Airline Transport Pilot Certificate | Governmental |
| After Tax Profit | Income Tax |
| ANANTAPUR | Indian Railway Station |
| Asociación de Traductores Profesionales, A.C. | International |
| AuToPropulsado | International |
| Asociaci? de Traductores Profesionales, A.C. | International |
| At This Point | Internet |
| As Time Permits | Internet |
| Air Transport Pilot | Jobs |
| adenosine (5'-)triphosphate | Medical |
| According To Protocol | Medical |
| Advanced Test in Psychology | Medical |
| Ambient Temperature and Pressure | Medical |
| Association for Teaching Psychology | Medical |
| Association for Transpersonal Psychology | Medical |
| Authority To Proceed | Medical |
| Acute Tonsilar pharyngitis | Medical |
| Adult Treatment Panel | Medical |
| ATtending Physician | Medical |
| Ammunition Transfer Point | Military and Defence |
| Acquisition Tracking and Pointing | Military and Defence |
| Acceptance Test Plan | Military and Defence |
| Allied Tactical Publication | Military and Defence |
| Advance Targeting Pod | Military and Defence |
| Asymmetric Transport Protocol | Networking |
| Appletalk Transaction Protocol | Networking |
| Aitape, Papua New Guinea | Regional |
| Automatic Train Protection | Regional |
| Alaska Teacher Placement | Regional |
| Australian Technology Park | Regional |
| Accelerated Training Program | Space Science |
| Acceptance Test Procedure | Space Science |
| Authorization To Proceed | Space Science |
| Active Time Penalty | Sports |
| Anonymous Tennis Players | Sports |
| Association of Tennis Professionals | Sports |
| American Tennis Promotion | Sports |
| Assistive Technology Partnership | Technology |
| Advanced Technology Partner | Technology |
| Assistive Technology Practitioner | Technology |
| Association of Telecom Professionals | Telecommunication |
